Battery systems typically include a plurality of individual batteries that are connected together to provide a single electrical power source. A “battery,” as used in this document, refers to a plurality of cells that are connected in series to provide electrical power to an electrical load. Each battery within a battery system has characteristics different than the other batteries. These characteristics include energy storage capacity and discharge rates. These differences can be caused by many variables including, but not limited to, temperature, initial tolerances, material impurities, porosity, electrolyte density, surface contamination, and age. A low-capacity battery typically discharges more rapidly than a higher capacity battery. An overly discharged battery can develop poor recharging characteristics and become permanently damaged. A damaged battery can reduce the effective life of the battery system. As the capacity of a damaged battery decreases, the battery discharges through the electrical load more rapidly than a healthy battery. Eventually, the characteristics of the batteries in the system can deviate so significantly from one another that the lower capacity batteries effectively destroy the ability of the battery system to power the load for a meaningful period of time. Therefore, a need exists for a system to monitor batteries in a battery system to detect weak batteries and recharge the batteries in the system in a manner that preserves the life of the battery system.